This research consists of a group of basic experiments in immunology and neoplastic lymphocyte cell biology. The model is that of the MOPC-315 plasmacytoma, an IgA, lambda2 secreting tumor with anti-TNP hapten specificity. A multiparameter study of cell surface antigens, cell-cycle phase distributions, and morphologic and functional characteristics of the tumor cells will be undertaken initially. This represents an effort to definitively assess the number and type of distinct differentation and/or activation states present in the tumor and will allow the measurement of changes in those states as the tumor undergoes spontaneous or T-cell and lymphokine-modulated growth in vivo and in vitro. Methods to be used initially include: (1)\monoclonal antibodies (raised specifically against 315 cell surface antigens); (2)\one-dimensional and two-dimensional polyacrylamide gel electrophoresis (to characterize the antigens); (3)\cell cycle analysis using viable and non-viable DNA dyes; (4)\fluorescence-activated cell analysis and sorting; (5)\in vivo implantation and retrieval of tumor cells in diffusion chambers; (6)\in vivo colony-forming assays; (7)\in vitro tumor tissue culture with and without lymphokine modulation; (8)\in vitro colony-forming assays; (9)\assays of cell growth (including direct counting and thymidine incorporation); (10)\assays of antibody secretion (including PFC and supernatant assays); and (11)\the producton of lymphokines. As the work progresses, our research will undertake analytical studies of the immunoglobulin messenger RNA populations associated with the distinct differentiation and/or activation states, and we will further study the changes in those RNA populations resulting from T cell or lymphokine modulation. These studies will involve the isolation and electrophoresis of polyadenylated mRNA, nitrocellulose blotting, and testing for the complementary binding of radiolabelled DNA probes specific for the heavy and light chain RNAs. These studies will contribute to the understanding of T cell immunoregulation of normal and neoplastic B lymphocytes. They may provide novel approaches to therapy and help provide a rational basis for further trials in idiotype-specific immunotherapy. (LB)